1. Field of the Invention
The present invention relates to a charge-coupled device for automatically focusing a camera and a camera shake detector using this charge-coupled device.
2. Description of the Prior Art
When an object of low brightness is photographed by a camera, the shutter speed of the camera is low, and any tendency of the camera to shake would result in a blurred or double image. Therefore, it has been customary to detect those shutter speeds lower than a certain shutter speed, which would cause a problem with respect to camera shake, and to give an indication to the user of a possible problem of camera shake.
One conventional camera shake detector utilizes an automatic exposure control device for detecting a possible camera shake based on information about the brightness of an object to be photographed. However, it is known that whether a camera will shake or not is related to not only the object brightness but also how fast the object is moving. More specifically, an orginary object which is still or moving slowly may not cause any camera shake at a certain shutter speed, but a fast moving object may produce a blurred image on the film at the same shutter speed. The prior camera shake detector fails to detect such a camera shake when photographing the fast moving object. The critical shutter speed below which camera shaking will take place also differs from user to user dependent on the skill of the user. No conventional camera shake detector has been designed to effect camera shake detection dependent on how skillful the user may be.